BS ISO 8769:2020 Measurement of radioactivity一Alpha-, beta- and photon emitting radionuclides一Reference measurement standard specifications for the calibration of surface contamination monitors.
National metrology institutes shall , at their discretion , provide the means whereby Class 1 reference
measurement standards of a specified range of radionuclides may be certified by them . For those
countries which are signatories to the Mutual Recognition Arrangement ( MRA ) , a certificate of
calibration from another participating institute in a second country is recognized as valid in the
first country for the quantities , ranges , and measurement uncertainties specified in Appendix C of
The activity and surface
rate of Class 1 reference measurement standards shall be measured
using , for example , a wi
gas-flow proportional detector , or by using an instrument that
been calibrated using
that have been measured absolutely . Calibration procedures
activity determination are discussed for example , in References [ 10 ] , ( 11 ) . [ 12 ] and [ 13
Organizations with a requirement to type test and to calibrate instruments to be used for monitoring
radioactive surface contamination need to have access to suitable Class 1 or Class 2 reference
measurement standards . The purpose of a working measurement standard is to check the calibration
of surface contamination monitors in the field ; they are not to be confused with check sources , which
are only intended to verify that a monitor is operating
Organizations with a requirement to provide working measurement standards for the routine
confirmation of the calibration of their surface contamination monitoring instruments require access to
a reference transfer measurement device with which to calibrate such working measurement standards
in terms of surface emission rate against a Class 1 or Class 2 reference measurement standard . Where
e working measurement standard is used either in a jig or under a particular geometry , the reference
transfer measurement device on which its emission rate is measured shall have been calibrated using a
reference measurement standard under identical conditions and geometry . Alternatively , the working
measurement standard shall be removable from the jig so that it can be measured in the usual way
Where only a few monitors need calibration or a high degree of accuracy is required , Class 1 or Class 2
eference measurement standards may be used as working measurement standards . In such cases , the
frequency of re-calibration shall be that for working measurement standards . National regulations may
require more frequent calibrations .BS ISO 8769 pdf download.